package upstream import ( "errors" "io" "net/http" "strings" "time" "github.com/rs/zerolog/log" "codeberg.org/codeberg/pages/html" "codeberg.org/codeberg/pages/server/context" "codeberg.org/codeberg/pages/server/gitea" ) const ( headerContentType = "Content-Type" headerETag = "ETag" headerLastModified = "Last-Modified" headerIfModifiedSince = "If-Modified-Since" rawMime = "text/plain; charset=utf-8" ) // upstreamIndexPages lists pages that may be considered as index pages for directories. var upstreamIndexPages = []string{ "index.html", } // upstreamNotFoundPages lists pages that may be considered as custom 404 Not Found pages. var upstreamNotFoundPages = []string{ "404.html", } // Options provides various options for the upstream request. type Options struct { TargetOwner, TargetRepo, TargetBranch, TargetPath, // Used for debugging purposes. Host string TryIndexPages bool BranchTimestamp time.Time // internal appendTrailingSlash bool redirectIfExists string ServeRaw bool } // Upstream requests a file from the Gitea API at GiteaRoot and writes it to the request context. func (o *Options) Upstream(ctx *context.Context, giteaClient *gitea.Client) (final bool) { log := log.With().Strs("upstream", []string{o.TargetOwner, o.TargetRepo, o.TargetBranch, o.TargetPath}).Logger() // Check if the branch exists and when it was modified if o.BranchTimestamp.IsZero() { branch := GetBranchTimestamp(giteaClient, o.TargetOwner, o.TargetRepo, o.TargetBranch) if branch == nil { html.ReturnErrorPage(ctx, "", http.StatusFailedDependency) return true } o.TargetBranch = branch.Branch o.BranchTimestamp = branch.Timestamp } if o.TargetOwner == "" || o.TargetRepo == "" || o.TargetBranch == "" { html.ReturnErrorPage(ctx, "", http.StatusBadRequest) return true } // Check if the browser has a cached version if ifModifiedSince, err := time.Parse(time.RFC1123, string(ctx.Response().Header.Get(headerIfModifiedSince))); err == nil { if !ifModifiedSince.Before(o.BranchTimestamp) { ctx.RespWriter.WriteHeader(http.StatusNotModified) return true } } log.Debug().Msg("preparations") reader, res, err := giteaClient.ServeRawContent(o.TargetOwner, o.TargetRepo, o.TargetBranch, o.TargetPath) if reader != nil { defer reader.Close() } log.Debug().Msg("acquisition") // Handle errors if (err != nil && errors.Is(err, gitea.ErrorNotFound)) || (res == nil) { if o.TryIndexPages { // copy the o struct & try if an index page exists optionsForIndexPages := *o optionsForIndexPages.TryIndexPages = false optionsForIndexPages.appendTrailingSlash = true for _, indexPage := range upstreamIndexPages { optionsForIndexPages.TargetPath = strings.TrimSuffix(o.TargetPath, "/") + "/" + indexPage if optionsForIndexPages.Upstream(ctx, giteaClient) { return true } } // compatibility fix for GitHub Pages (/example → /example.html) optionsForIndexPages.appendTrailingSlash = false optionsForIndexPages.redirectIfExists = strings.TrimSuffix(ctx.Path(), "/") + ".html" optionsForIndexPages.TargetPath = o.TargetPath + ".html" if optionsForIndexPages.Upstream(ctx, giteaClient) { return true } } ctx.Response().StatusCode = http.StatusNotFound if o.TryIndexPages { // copy the o struct & try if a not found page exists optionsForNotFoundPages := *o optionsForNotFoundPages.TryIndexPages = false optionsForNotFoundPages.appendTrailingSlash = false for _, notFoundPage := range upstreamNotFoundPages { optionsForNotFoundPages.TargetPath = "/" + notFoundPage if optionsForNotFoundPages.Upstream(ctx, giteaClient) { return true } } } return false } if res != nil && (err != nil || res.StatusCode != http.StatusOK) { log.Printf("Couldn't fetch contents (status code %d): %v\n", res.StatusCode, err) html.ReturnErrorPage(ctx, "", http.StatusInternalServerError) return true } // Append trailing slash if missing (for index files), and redirect to fix filenames in general // o.appendTrailingSlash is only true when looking for index pages if o.appendTrailingSlash && !strings.HasSuffix(ctx.Path(), "/") { ctx.Redirect(ctx.Path()+"/", http.StatusTemporaryRedirect) return true } if strings.HasSuffix(ctx.Path(), "/index.html") { ctx.Redirect(strings.TrimSuffix(ctx.Path(), "index.html"), http.StatusTemporaryRedirect) return true } if o.redirectIfExists != "" { ctx.Redirect(o.redirectIfExists, http.StatusTemporaryRedirect) return true } log.Debug().Msg("error handling") // Set ETag & MIME if res != nil { ctx.Response().Header.Set(headerETag, res.Header.Get(headerETag)) if o.ServeRaw { ctx.Response().Header.Set(headerContentType, res.Header.Get(headerContentType)) } else { ctx.Response().Header.Set(headerContentType, rawMime) } } if ctx.Response().StatusCode != http.StatusNotFound { // Everything's okay so far ctx.Response().StatusCode = http.StatusOK } ctx.Response().Header.Set(headerLastModified, o.BranchTimestamp.In(time.UTC).Format(time.RFC1123)) log.Debug().Msg("response preparations") // Write the response body to the original request if reader != nil { _, err := io.Copy(ctx.RespWriter, reader) if err != nil { log.Printf("Couldn't write body: %s\n", err) html.ReturnErrorPage(ctx, "", http.StatusInternalServerError) return true } } log.Debug().Msg("response") return true }